Edith Arangoitia, 46, (who came along with her elderly mother) will be vaccinated with the Pfizer-BioNTech Covid-19 vaccine on February 16, 2021 by Dr. Galen Harnden at La Colaborativa in Chelsea, Massachusetts.
Joseph Precious | AFP | Getty images
Dr. Anthony Fauci, chief medical adviser to the White House, said on Monday that Americans should continue to receive two doses of the Pfizer and Moderna Covid-19 vaccines, despite a recent US study that found the injections to be very effective after just one dose.
A Centers for Disease Control and Prevention study published last week found that a single dose of Pfizer or Moderna’s Covid-19 vaccine was 80% effective in preventing coronavirus infections among medical personnel and other key workers. Two doses are better than one, federal health officials said, adding that the effectiveness of the vaccines has increased to 90% two weeks after the second dose.
While the 80% figure was great news, Fauci said on Monday he is still concerned about the duration of the protection after a single dose, especially with the emergence of highly contagious variants that have shown they can protect the vaccines. circumvent.
“If you look at the level of protection after one dose, you can say it’s 80%, but it’s a slightly weak 80%,” Fauci said during a White House newsletter on the pandemic. “If you leave it in one dose, the question is how long will it last?”
Highly contagious Covid-19 variants that have shown some resistance to vaccines also pose a challenge, Fauci said. “You’re in a fuzzy zone when you don’t have the full impact” of two doses, he said.
Fauci’s comments come because some health experts and public health officials argue that the US should prioritize giving Americans just one dose of the vaccines before moving to second doses, accelerating the pace of vaccinations across the country.
Unlike the Johnson & Johnson vaccine, which requires one dose, the Pfizer and Moderna vaccines require two injections three to four weeks apart. In the UK, health officials decided to increase the time between the first and second dose to 12 weeks to speed up vaccinations.
Fauci has repeatedly said in recent months that the US should adhere to the two-dose regimen.
Dr. Paul Offit, a voting member of the FDA’s Vaccines and Related Biological Products Advisory Committee who reviewed both Pfizer’s and Moderna’s vaccines for emergency authorization, told CNBC last week that studies have shown that immunity actually appears to be “ more durable ” after the second dose, which means that protection may last longer.
The two-dose vaccination regimen also produces 10 times the amount of neutralizing antibodies, which play an important role in fighting the virus, from the first to the second dose, Offit told CNBC.
Second, and more importantly, scientists also discovered so-called T cells after the second dose, another important part of the immune response that usually provides long-lasting immunity, he said.
Fauci said Monday he “respects” arguments for a one-dose strategy, but added that the US currently has enough doses to give Americans a first and second dose. “Although we always remain open, we consider the route we are taking as the best route,” he said.